Introduction to the new mainfame

Introduction to the new mainfame

© Copyright IBM Corp., 2005. All rights reserved.

Chapter 12: Databases

Introduction to the new mainframe


ObjectivesIn this chapter, you will learn:

• DB2 concepts• The DB2 system structure• DB2 for z/OS architecture• How to invoke SQL on z/OS• Application programming with DB2• Managing DB2• IMS-DB



Key terms in this chapter• unit of work• DBMS• SPUFI• SQLJ• SYSADM• EXPLAIN• view• modified source



DB2 Concepts: Data Structures

VSAMLDS

VSAMLDS

Storage group

Data base

Table Space

Table

Index Space

Index

Views



Schema structures

• User-defined Data Type (UDT)• User-defined Function (UDF)• Triggers• Large Object (LOB)• Stored Procedure



System Structure

Catalog and Directory: stores ALL DB2 informationBuffer PoolActive and Archive LogsBootstrap data set (BSDS)



DB2 for z/OS ArchitectureDB2 Address Spaces

• System Service address space (SSAS)• Database Service address space (DBAS)• Internal Resource Lock Manager (IRLM)

DB2 Attachment Facilities• CICS• IMS• TSO



Invoke SQL on z/OS: SPUFI

Select option 1 to enter SPUFI

First you need to create the output file (if not existing)



Invoke SQL on z/OS: SPUFI (continued)

Enter the input and output dataset, if they are not yet in place.Change the member of the PDS, if you want to enter a new SQLDefaults are set to NO from YES.




Enter the SQL statement you want to execute. Press F3 to return to the previous screen (to execute the SQL).




When you get back to this screen, the “edit input” is put to “*”.Press ENTER to execute the SQL and to see the output.




F8 brings the rest of the results on your screen



Application Programming: the flow

SourceSourceProgramProgram

Precompile

IncludeIncludeMemberMember

Compile

Linkedit

ModifiedSource

Object Module

Load Module

DBRM

Bind

Package

Bind

Plan

DCLGEN

RUN



Get the access path: EXPLAIN

EXPLAIN ALL SET QUERYNO = 1SELECT EMPNO, LASTNAME

FROM EMPWHERE LASTNAME = 'MILLER';

-The query is NOT executed-The access path is placed in userid.PLAN_TABLE, if it exists



Other development options

• ODBC• JAVA• SQLJ• JDBC• XML• XML Column Access• XML Collection Access



Managing DB2: System Administration

InstallationSystem Object ManagementSystem and Disaster RecoveryMonitoring System Performance



Managing DB2: Database Administration

Creation and management of DB2 objectsExecution of utilities:

• Data Organization• Backup and recovery• Data Consistency

Commands



Functions of the IMS DM

A DBMS provides:• A single copy of data for access by multiple users • Maintenance of integrity across all updates• Minimization of HW and OS access method

dependencies• Reduction of data redundancy



Implementation of IMS Databases

Depending on user requirementsTechnologies :

• IMS DB or DL/I or DL1 or Full Function Database

• IMS DEDB or Data Entry DB or Fast Path Database

• IMS Main storage database (MSDB)

• IBM DB2

Database Recovery Control (DBRC)



Structure of IMS DB Subsystem

System Address SpaceApplication Region Address Space

Up to 99 in total

DLISeparateAddressSpace

DBRCRegion

MPP IFP BMP

ApplicationProgram

Full Function DBs RECONs

DependentRegion

AddressSpace

IMS System

IMS Libraries

IMS Message Queues

Logs

Fast Patch DBs

ControlRegion

AddressSpace

Network

JavaMessage

Processing

JavaBatch

ProcessingApplicationProgram

ApplicationProgram



Databases used by IMS: Database basics

Access pathsNormalization within IMS

• Unique entities• One occurrence only• No many-to-many relationships



Databases used by IMS: DB ModelSequence to access the segments

ROOT(1)

Segment A2(8)

Segment A1(2)

Segment D3(9)

Segment D2(4)

Segment E3(7)

Segment D1(3)

Segment E2(6)

Segment E1(5)

Segment B2(14)

Segment B1(10)

Segment G2(12)

Segment H1(13)

Segment G1(11)



Databases used by IMS: DB model

Additional access paths to segments• Logical relationships• Secondary indices



Application programming overview

Program is subroutine of IMS region controller• Needs a program specification block (PSB)• Uses services:

• Send/receive message from terminals• Access db• Issue IMS commands• Issue IMS service calls

example: Checkpoint calls, Sync call



Program Structure

Segments Segments to/from to/from

databasesdatabases

ENTRy

EXIT

DLI modules

Call infoCall infofrom DLIfrom DLI

PCB-Mask

IO AREA

Application Program

PROGRAM ENTRYDEFINE PCB AREASGET INPUT RECORDS FROM INPUT FILECALLS TO DL/I DB FUNCTIONS

RETRIEVEINSERTREPLACEDELETE

CHECK STATUS CODESPUT OUTPUT RECORDSTERMINATION



IMS and the World Wide WebMessage flow in IMS transactions

3270 Terminal

1,2

VTAM IMS MPP

3 4,5

8,9 7 6

NCP



IMS and the World Wide WebMessage flow between Web browser and Web server

Web Browser

1,2

WebServer

CGIProgram

3 4,5

8,9 7 6

TCP/IP TCP/IP



IMS and the World Wide WebMessage flow IMS transaction and Web server CGI programs

3270 Terminal

1,2

VTAM IMS MPP

3 4,5

8,9 7 6

NCP

Web Browser

1,2

WebServer

CGIProgram

3 4,5

8,9 7 6

TCP/IP TCP/IP

Program to ProgramCommunications



SummaryIn this chapter, you learned:

• Some DB2 concepts• The DB2 system structure• DB2 for z/OS architecture• How to invoke SQL on z/OS• Application programming with DB2• Managing DB2• IMS-DB

Introduction to the new mainfame


Database Exercises



DB2 Interactive



Default panel 1



Default panel 2



DCLGEN



Do the exercise• Do the DCLGEN• Execute the SQL (change it if you want)• Change the program• Execute the job



Execute from TSO Allocate your datasets first (1)Change your parameters and press enter (2)

1

2

2



Execute from TSO (continued): results

Introduction to the new mainfame

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